List of top Chemistry Questions

Match the following:

List-I (Atomic number, Z)	List-II (Block)
A) 112	I) \(s\)
B) 116	II) \(p\)
C) 88	III) \(d\)
D) 100	IV) \(f\)

Observe the following numbers:
I) 0.0063
II) 132.00
III) 1004
The number of significant figures in I, II and III respectively is

Observe the following reactions
I) Sucrose (aq) + H2O →[x] glucose + fructose
II) Glucose (aq) →[y] ethanol + CO2
What are $x$ and $y$ respectively? Identify the correct option from the following:

Consider the following statements:
Statement-I: CH$_3$NH$_2$ is more basic than NH$_3$, but C$_6$H$_5$NH$_2$ is less basic than NH$_3$.
Statement-II: The order of basic strength of amines in aqueous phase follows
(C$_2$H$_5$)$_2$NH > C$_2$H$_5$NH$_2$ > C$_6$H$_5$NH$_2$

The most acidic carboxylic acid is:

In the following sequence of reactions, what is the end product (D)?
C$_2$H$_5$Br $\xrightarrow{\text{KCN}}$ A $\xrightarrow{\text{H$_3$O$^+$}}$ B $\xrightarrow{\text{LiAlH$_4$}}$ C $\xrightarrow{\text{Cu, 573 K}}$ D

The structure of the nitrogen-containing heterocyclic base shown below represents:

What are X and Y respectively, in the given set of reactions?

CH3CH2CH2Cl

What is the drug used to control depression and hypertension?

A carbonyl compound X(C$_5$H$_8$O) gives yellow precipitate with NaOI. Hemiacetal of X with methanol/dry HCl is:

Which of the following does not involve in Friedel-Crafts reaction?

The ion with 4f$^7$ configuration is:

Consider the following.
Statement-I: Gold sol is prepared by Bredig’s arc method.
Statement-II: Bredig’s arc method involves only dispersion but not condensation.

The oxides of nitrogen obtained by the reaction of nitric acid with

Which of the following sets are correctly matched?
I) Hg — distillation
II) Cu — poling
III) B — zone refining
IV) Ti — liquation

Which of the following is the common monomer for the polymers Bakelite and Melamine?

The catalyst used for the isomerisation of n-alkanes to branched chain alkanes is:

Identify the catalytic reaction in which both reactants are in different phases.

Identify the air pollutant which in high concentration leads to stiffness of flower buds?

$H_2O_2$ with $KMnO_4$ in acidic medium gives a manganese compound 'X' and in basic medium gives another manganese compound 'Y'. The oxidation states of manganese in X and Y respectively are:

Match the following:

List-I (Compound)	List-II (Use)
A) Kieselguhr	IV) To convert alcohol directly into gasoline
B) Silica gel	I) Chromatographic material
C) ZSM-5	III) Filtration plants
D) Hydrated zeolites	II) Softening of hard water

Which of the following orders are correct against the stated property?
I) NaO$_2 < KO$_2 < RbO$_2 < CsO$_2$ — stability
II) Mg(OH)$_2 < Ca(OH)$_2 < Sr(OH)$_2$ — basic strength
III) MgCO$_3 < CaCO$_3 < SrCO$_3$ — thermal stability

In the structure of diborane, the number of 2-centre-2-electron bonds is X and 3-centre-2-electron bonds is Y. The value of (X + Y) is:

Consider the following
Statement-I: During isothermal expansion of an ideal gas its enthalpy decreases.
Statement-II: When 2.0 L of an ideal gas expands isothermally into vacuum, $\Delta U = 0$.

At 25$^\circ$C, the percentage of ionization of x M acetic acid is 4.242. What is the pH of the acetic acid solution?
Given: $\log 4.242 = 0.6275$, $\log 0.04242 = -1.372$, $K_a = 1.8 \times 10^{-5}$